Compressed air driven disposable hand tool having a rotor with radially moving vanes

Abstract

A fluid reaction device (10) is provided having a rotor (90) with vanes (92) pivotably connected thereto. The device (10) includes an entrance (30) for elevated pressure fluid and an outlet (40) for discharge of the fluid after contacting the rotor (90). The elevated pressure fluid passes from the entrance (30) into a high pressure area. The high pressure area is in contact with inlet ports (74) accessing a cylinder (70) within the device (10). The cylinder (70) supports the rotor (90) with a rotational axis (M) of the rotor (90) off center with respect to a central axis (N) of the cylinder (72). The elevated pressure fluid causes the rotor (90) and an attached output shaft (97) to rotate. The rotor (90) includes a trunk (24) with a plurality of posts (93) extending therefrom and with vanes (92) connected to the posts (93) through hinges (94). The vanes (92) can pivot from a first position collapsed against the trunk (24) to a second position spaced away from the trunk (24). The vanes (92) thus can contact a cylindrical wall of the cylinder (70) while the rotor (90) rotates. Exhaust ports (76) are spaced from the inlet ports (74) and provide communication with a low pressure area which exhausts low pressure fluid to the outlet (40).

We claim: 
     
       1. A plastic, disposable rotary hand tool device receiving fluid as input and having a rotating shaft as output, comprising, in combination: a rotor including an integrally formed substantially rigid trunk, a plurality of vanes, and a hinge means to pivotably attach said vanes to said trunk said vanes having a center of mass spaced from said hinge means;   a hollow cavity formed within a housing, said cavity including means to inlet fluid into said cavity parallel to an axis of rotor rotation, means to exhaust fluid out of said cavity, and means to rotatably support said trunk of said rotor within said cavity; and   an output shaft coupled to said rotor such that when fluid enters said cavity, said shaft is caused to rotate,   said housing having an output end with a bend, said housing having a swivel means adjacent said output shaft to allow reorientation of said housing with respect to said bend.   
     
     
       2. The device of claim 1 wherein said bend includes a first gear parallel to a long axis of said device and a second gear coupled to said first gear and skewed from said long axis. 
     
     
       3. The device of claim 2 wherein said means to rotatably support said rotor within said cavity includes a means to support said rotor with a rotational axis of said rotor spaced from a central axis of said hollow cavity. 
     
     
       4. The device of claim 3 wherein a seal point is provided between said rotor and said cavity, said seal point located between said inlet means and said exhaust means, said seal point defined by at least one portion of said rotor contacting said cavity between said inlet means and said exhaust means, whereby fluid passing through said inlet means and into said cavity is prevented from accessing said exhaust means by passing around a side of said rotor closest to said seal point.   
     
     
       5. The device of claim 4 wherein said rotor includes a recess adjacent each vane, each said recess having a contour which can receive an adjacent said vane therein when said vane is pivoted about said pivotable attachment means. 
     
     
       6. The device of claim 5 wherein said pivotable attachment means includes a hinge interposed between at least one of said vanes and said trunk, said hinge including means to apply a force causing extension of said vane out of an adjacent said recess. 
     
     
       7. The device of claim 6 wherein said inlet means includes at least one inlet port passing through said cavity, said inlet ports in fluid communication with a source of elevated pressure compressible fluid. 
     
     
       8. The device of claim 7 wherein said outlet means includes at least one outlet port passing through said cavity, said outlet ports in fluid communication with a region having lower pressure than said source of elevated pressure compressible fluid. 
     
     
       9. The device of claim 8 wherein said hollow cavity has an inside wall which exhibits a radius of curvature adjacent said seal point greater than a radius of said rotor when said vanes are collapsed against said trunk, and wherein said vanes include tips distant from said hinge, said tips of said vanes positioned to allow contact with said wall of said cavity at all times, whereby compressible fluid is prevented from passing from said inlet ports to said outlet ports without rotor rotation. 
     
     
       10. The device of claim 9 wherein said hollow cavity is defined by an insert nested within a substantially cylindrical housing, said insert having an outer diameter less than an inside diameter of said housing, whereby elevated pressure compressible fluid leaves a source of elevated pressure compressible fluid, passes through said entrance into said housing, through said inlet ports, around said rotor on a side of said rotor opposite said seal point causing said rotor to rotate, out of said exhaust ports, into said low pressure chamber, and exits said housing through said outlet, thereby converting elevated pressure compressible fluid into a combination of low pressure compressible fluid and rotor rotation.   
     
     
       11. The device of claim 9 wherein said trunk of said rotor includes a plurality of posts extending from said trunk, each said post including one of said hinges, each said vane having a shape which allows said vane to be pivoted into an adjacent said recess.